Depending on the reference, pin track infection rates in external fixation surgery have been stated to be anywhere from 0% to 100%. We critically evaluated the pin track infection rate for external fixation by performing systematic review of the external fixation literature since 1980. Using PubMed, a search of the peer-reviewed literature on external fixation was performed. This systematic review was conducted, as much as possible, in accordance with PICOS and PRISMA guidelines. A total of 150 articles were reviewed, including at least one from each year between 1980 and 2014. The following data were collected from each article: the year of publication, number of patients in the study, average age of the patients, reason for the external fixation, fixation per segment (two or more than two points), body part involved, whether or not hydroxyapatite-coated pins were used, duration of the external fixator, type of fixator used, and number of patients with documented pin track infections. These 150 studies represented 6130 patients. There were 1684 reported pin track infections from these 6130 patients, giving a cumulative pin track infection rate of 27.4%. A more recent year of publication was associated with an increasing infection rate (P = 0.015) while increasing age was associated with a decreased infection rate (P < 0.0005). There were trends toward association of humerus location (P = 0.059), shorter fixator duration (P = 0.056), and circular fixation (P = 0.079) with decreased infection rates. This systematic review of external fixation publications revealed a cumulative pin track infection rate of 27%. Younger age was the factor leading to increased pin track infection rates. Circular fixation trended toward being protective of pin track infection when usage was factored into the multiple regression analysis. Longer duration of fixation trended toward increased infection rate as expected. This data provides important base values for a common complication in external fixation treatment, highlights the importance of a more consistent definition of a pin track infection in future research, and identifies the pediatric population as the group at greatest risk.

Context: Hexapod fixators can be divided into two basic design groups. One group consists of frames that use ball and socket joint struts attached to the outer surface of the rings. The other group consists of frames that use cardan type universal joint struts attached to the under surface of the rings.
Aims: To compare the ability of different hexapod fixator systems for deformity correction.
Settings and Design: Nearly, identical two-ring frame constructs were compared to determine if there was any difference in deformity correction capability between cardan type universal joint struts and ball and socket joint struts.
Materials and Methods: Maximal deformity was created using the software for each of the frame constructs in all six planes of deformity (angulation, translation, and rotation in the coronal and sagittal planes). Clinical scenarios were also compared (equinus contracture, moderate Blount disease, and severe Blount disease) and the number of strut changes necessary to correct the deformity were recorded.
Results: For the small and medium-sized struts, the angular deformity corrections were similar, but the cardan type universal hinges had a greater capability for correcting translational deformity and rotation than the ball and socket joints. However, the amount of lengthening possible was greater for the ball and socket joints with these strut sizes. In the largest size of struts, the ball and socket joints had greater range in every category except rotation. In patients requiring significant rotational correction, the cardan type universal joints were found to impinge on the soft tissues 13° earlier than the ball and socket joints (39° vs. 52°). A Blount disease case with moderate multiplanar deformity and an equinus correction of 45° required the same amount of strut changes for each design. For the Blount disease case with severe multiplanar deformity, the cardan type universal joint struts required six total changes, whereas the ball and socket joint struts required only one strut change and two strut adjustments to achieve the same correction.
Conclusions: Both the cardan type universal joint and the ball and socket joint hexapod frame designs allow substantial multiplanar corrections to occur. In the smaller size struts, the cardan type universal joints allow more translation and rotation, whereas the ball and socket joints allow more length. For large rotational corrections and frames built with 90° of offset, the ball and socket joint design is better at avoiding soft tissue impingement. While both systems are comparable with mild to moderate deformity correction, the ball and socket joint design allows more correction with less strut changes for patients with severe deformity in our experimental construct.

The management of large bone defects, atrophic nonunions, and other conditions with poor bone formation presents a formidable challenge to the treating physician, as all available techniques of bone reconstruction have drawbacks. Recent advances in stem cell biology, specifically adipose tissue-derived mesenchymal stem cells (ASCs) and adipose tissue stromal vascular fraction (SVF), have opened up new horizons by providing a reliable and abundant source of stem cells with osteogenic potential that can be used in various bone tissue engineering techniques. In this review, several aspects related to the use of ASCs are addressed, such as harvesting and processing of adipose tissue, advantages of ASCs over bone marrow-derived mesenchymal stem cells, mechanism of action and safety of ASCs, and factors affecting the differentiation of ASCs. Published reports on the use of ASCs in critical size defects, nonunions, and distraction osteogenesis are also reviewed. Innovative trends in stem cell research on musculoskeletal pathologies are highlighted, with special emphasis on the increasing evidence that the direct application of freshly prepared SVF processed from adipose tissue into the bone defect to be treated without a prior differentiation or an ex vivo expansion and culture is possible. This highly promising approach may lead to the development of a one-step intraoperative cell therapy.

Background: Despite the large negative effect of limb deformity on health-related quality of life (QoL), there exists no patient-reported instrument to quantify this impact. Rather, limb deformity research has been performed using global QoL measurements concurrently with joint-specific and/or arthritis outcome scales, thereby requiring the completion of multiple instruments. Furthermore, joint- and arthritis-specific instruments focus on the impact pain has on function, whereas limb deformities may be pain-free with greater social and functional impairment. The purpose of this study was to validate a patient-reported instrument to quantify limb deformity-related QoL.
Materials and Methods: Because of the similarities with regard to pain, function, and body image between limb deformity and scoliosis, the Scoliosis Research Society-30 (SRS-30) spine deformity instrument was modified such that the words "back" and "trunk" were replaced with "limb" to create a novel instrument: the limb deformity-SRS (LD-SRS). Testing for construct validity (both convergent and discriminant), reliability, floor and ceiling effects, and minimal clinically important difference (MCID) was performed in a validation cohort of 62 subjects aged 18 years or older with nonarthritic, unilateral lower extremity deformity.
Results: Scale reliability was excellent (test-retest reliability, intraclass correlation coefficient = 0.977; internal consistency, Cronbach's alpha = 0.906), scores were normally distributed, and there were no floor or ceiling effects. There was also robust construct validity: convergent validity testing revealed positive correlations between the LD-SRS and all short-form-36 domains, the American Academy of Orthopaedic Surgeons-Lower Limb Module, and higher scores in those who were postcorrection. Discriminant validity was demonstrated with no correlations between the LD-SRS and subject age, sex, body mass index, surgeon-scored Limb Lengthening and Reconstruction Society-AIM Index, or surgeon-generated deformity measurements. MCID was calculated to be 0.3 (on a 4.0-point scale).
Conclusions: The LD-SRS score is a reliable and valid instrument to measure limb deformity-related QoL in patients with nonarthritic lower extremity deformity. It is a valuable tool which allows clinicians to quantify patients' deformity-related QoL with a single instrument, rather than repurposing scales which have been validated for other conditions and have limited applicability to the unique challenges of treating patients with a lower limb deformity.
Level of Evidence: Diagnostic, Level 2.

Pin-track infections are a common problem with external fixation and any other implant that breaks the skin barrier. The literature is rich with reports and techniques for treating these infections, but lacks a universally accepted definition of a pin track infection, a single commonly accepted classification, or a standard method of reporting. However, the surgeon can follow a commonly accepted series of practical steps to reduce the occurrence of infection. Continuing development of improved surfaces, substances, and techniques may make pin track infections rarer in the future. Careful preoperative planning, meticulous surgical technique, patient education, and close patient monitoring are all critical to minimize pin-track infections.

An elite-level 13-year-old female overhead athlete, with a previous history of bone cyst and fracture at age 8, presented with a humeral length discrepancy of 75 mm which had increased to 81 mm within 1 year. Antegrade correction with a motorized lengthening nail was considered but declined due to risk of shoulder damage and pain. In an off-label manner, a femoral motorized lengthening nail was modified and utilized with retrograde placement. Lengthening instructions were modified weekly to account for rapid humeral growth, to minimize soft-tissue tension, and to maximize regenerate quality. By 11 weeks, humeral length was clinically corrected. Three weeks after ceasing lengthening, full range of motion of the shoulder and elbow returned. Once the site had formed new cortex on all four sides, the nail was removed, and return to full activity occurred 4 months later.

The medial compartment osteoarthritis (OA) of knee joint has various surgical options such as high tibial osteotomy (HTO), hemiarthroplasty, and total knee arthroplasty. In the early stages of medial OA, there are no intra-articular deformities. Thus HTO, which is an extra-articular osteotomy, is recommended for the treatment of mild OA, but in moderate and severe medial OA, there are intra-articular deformities. HTO cannot correct these intra-articular deformities. Thus, an intra-articular osteotomy like the Tibial condylar valgus osteotomy (TCVO) is required in cases of moderate to severe medial OA knee. The contact area of the articular surface of the knee joint after TCVO is broader than it is after HTO in cases of moderate/severe OA. TCVO also improves the bony stability, eliminates the lateral thrust and surely corrects the alignment of the lower limb. To conclude, in cases of medial OA knee, the type of deformity must be evaluated and corrected accordingly. Intra-articular deformity must be corrected first. If the correction of varus and the mechanical axis is not enough, then extra-articular deformity must also be corrected, with a simultaneous or subsequent HTO.

Objective: The objective of this study is to determine the inter- and intra-observer reliabilities of three regenerate classifications (pixel value ratio [PVR], Ru Li and Donnan) in pediatric patients undergoing femoral or tibial distraction osteogenesis (DO). Methods: One hundred and forty regenerate radiographs (12 consecutive patients) were analyzed by using two observers using each classification system at two-time points. Inter and intra-observer reliabilities were calculated. Results: PVR and Ru Li demonstrated good, and Donnan demonstrated moderate to good inter- and intra-observer reliability. Two regenerate fractures occurred. Conclusion: Each classification can be reliably applied to pediatric DO. The PVR method of regenerate evaluation is ideal as it is simple and objective and can be used with readily available imaging software. The regenerate fractures identified in this study occurred in patients with longitudinal limb deficiency.

Background: The Ponseti method for clubfoot treatment was initially described for children up to 6 months. Remodeling of cartilage in infants undergoing treatment by Ponseti method has already been studied with magnetic resonance imaging (MRI). “Neglected” or after walking age clubfeet was also shown to be corrected with the Ponseti method. Remodeling in those patients has not yet been sequentially documented. Questions/Purposes: To document cartilage anlage changes at 2. 5 and 18 weeks during treatment in a 7-year-old child, and verify if those changes are maintained 2.5 years after Ponseti treatment. Does the Achilles tendon also heal and remodel? Materials and Methods: A 7-year-old with bilateral clubfeet is treated with Ponseti method with ten casts, followed by complete percutaneous tenotomy and anterior tibial transfer to the third cuneiform. Cartilage and bone remodeling are studied through MRI sequences at the beginning of treatment, 5, 18 weeks and 2.5 years after Ponseti clubfoot treatment. Results: Images before treatment show severe tibiotalar plantar flexion, plantar talar neck inclination, and inferior talonavicular subluxation. After 5 weeks images show the correction of hindfoot equinus. After 18 weeks images demonstrate correction of the tibiotalar plantar flexion, normal congruency of the talonavicular and subtalar and complete healing of Achilles tendon. These cartilage/bone changes are maintained after 2.5 years, and the foot is plantigrade. MRI studies after treatment show good congruency, and reduction of talonavicular, talocalcaneal, and calcaneocuboid joints. Healing of Achilles tendon is documented after 8 weeks of complete tenotomy, and anterior tibial tendon transfer can be identified inserted to the third cuneiform. Conclusions: The observed changes can justify application of Ponseti Method for children with clubfeet after walking age. Clinical Relevance: Ponseti treatment can be applied to children over walking age resulting in correction of clubfeet due to cartilage remodeling.

Background: Hexapod external fixators often incorporate bone lengthening as part of a multi-planar deformity correction plan. The hexapod struts, however, do not distract in the direction of bone lengthening. Their oblique orientation to the ring creates a vector that is the summation of multiple individual strut adjustments. We demonstrate that a 1 mm lengthening of each of all six struts always created more than 1 mm of lengthening at the bone. Methods: The amount of lengthening was analyzed with the Taylor Spatial Frame™ (Smith and Nephew, Memphis, TN, USA) software using two different methods. Results: As the strut lengths got longer the ratio got closer to one but it never reached 1.0. Conclusions: This information is critical when using very short struts or very large rings. In these two scenarios, the Δ frame height relative to the Δ strut length becomes much greater than one. Clinical Relevance: A strut length much greater than one will cause the bone to lengthen much faster than the surgeon desires. It may also lead to unhealthy regenerate bone formation and could create delays in bone healing.

Treatment of open fractures of the tibia with a locked intramedullary nail with a core release of antibiotics (SAFE DualCore Universal): Comparative study with a standard locked intramedullary nailNuno Craveiro-LopesJanuary-June 2016, 2(1):17-22DOI:10.4103/2455-3719.182571

Introduction: The SAFE Dualcore Universal Nail is an interlocking nail with an antibiotic cement core. We compared the clinical and radiological results with a standard interlocking nail for treating open fractures of the tibia.
Materials and Methods: Prospective, controlled cohort trial, including thirty patients with open fractures of the tibia. Patients were divided into two groups according to the treatment method: Group I (STD), consisting of 14 patients treated by delayed interlocking standard nailing, after an antibiotic treatment and bed rest. Group II (SAFE) had 16 patients treated with an interlocking intramedullary nail with a core of polymethyl methacrylate cement with antibiotics. Five of these were temporarily stabilized with an external fixator. We added vancomycin (2 g) and flucloxacillin (2 g) to the bone cement in the core of the nail. The two groups were similar on demographic data (age, gender), fracture, and extent of the wounds (P > 0.05). The mean follow-up was 2.4 years (5 months to 4 years) for the STD group and 2.1 years (4 months to 3 years) for the SAFE group.
Results: Fifteen of the 30 patients had positive cultures, including 13 cases growing Enterobacter, Enterococcus, Pseudomonas, and methicillin-susceptible Staphylococcus aureus (MSSA) groups. The infection rate was significantly more in STD at 43% (6/14 patients) compared to SAFE 6% (1/16 patients), (P = 0.02). Healing times was significantly more for STD group, at an average of 7.5 months (3-18 months) compared to 4.5 months (2-8.5 months) for the SAFE group (P = 0.02). The complication rate was 64% (9/14) in the STD group and 25% (4/16) for the SAFE, including the infection rate, a statistically significant difference (P = 0.03). The six infected STD nailing cases were salvaged with antibiotic coated cement nails, five of which healed. Infection recurred in the sixth case and was treated with the Ilizarov method.
Conclusion: SAFE nails had lesser infection, faster consolidation, and fewer complications compared with standard nails in treating open fractures of tibia. We can choose the type and dose of antibiotics eluted by the nail. The SAFE DualCore Universal nail is mechanical stable as well as biologically active. It allows fixation of intermediate bone segments, shortens hospital stay, healing time, and reduces the cost of treatment.
Level of Evidence: Level III.

Use of the Fassier-Duval telescopic rod for the management of congenital pseudarthrosis of the tibiaMohammad Mesfer Alzahrani, François Fassier, Reggie C HamdyJanuary-June 2016, 2(1):23-28DOI:10.4103/2455-3719.182572

Introduction: Congenital pseudarthrosis of the tibia (CPT) is a rare condition that can pose a challenge in achieving union after surgical excision of the pseudarthrosis site. Multiple methods have been described for management of fractures complicating this abnormal bone, including intramedullary nails (IMNs) and external fixators. One of the IMN designs is the telescoping nail, which has many models including the Fassier-Duval (FD) rod. This system has been known for its use in the management of osteogenesis imperfecta and different types of dysplasia. In this series, we describe our experience with the use of this system in the management of CPT of the tibia in children.
Methods: We conducted a retrospective chart review of four patients with FD rod insertions for CPT management. The mean age at surgery was 7.6 years (range: 1.5-17) and the minimum follow-up was 20 months (average: 52.3 months, range: 20-93 months). Two out of the four patients had a concomitant diagnosis of neurofibromatosis Type 1.
Results: All four cases achieved union of the fracture at final follow-up. Complications encountered in these cases included a case of joint intrusion into the knee and a case of rod migration due to the failure of telescoping.
Conclusion: The FD rod showed promising results in our cohort, but before this treatment modality can be recommended for the management of CPT, additional studies are required.
LevelofEvidence: IV

Introduction: Knee flexion contracture (KFC) is a debilitating condition that may affect patients with neurogenic conditions, congenital deformities, posttraumatic deformities, and after total knee replacement. The recurrence rate of the deformity following either operative or nonoperative treatment remains high. The aim of the present study is to assess clinical outcomes of patients with KFCs and associated ankle equinus using gradual correction with a circular external fixator (CEF).
Methods: Twenty-one patients with knee flexion contraction were treated using a CEF. Seven patients were also simultaneously treated for ankle equinus. All but two patients underwent a combination of open or arthroscopic knee arthrolysis, distal hamstrings lengthening, and gastrocsoleus release. The CEF was applied to match the residual deformity, following the minimal incision soft-tissue release.
Results: Mean follow-up was 13 months. The mean range of motion (ROM) at final follow-up was −10° extension, 64° flexion, 9° ankle dorsiflexion, and 29° ankle plantar flexion. The difference between preoperative and postoperative ROMs was statistically significant (P < 0.05).
Discussion: The present study suggests that gradual distraction using a CEF is a safe and effective technique in the management of KFC and concurrent ankle equinus. It is crucial to maintain the postoperative correction with braces for at least 1-3 months, depending on the severity of the condition.

Background: This study aimed to compare two techniques of syndesmotic fixation in terms of preventing lateral malleolus migration and ankle malalignment during tibial lengthening.
Methods: Children who had tibial lengthening > 20 mm using Taylor Spatial Frame were included. Two techniques of syndesmotic fixation were evaluated: Transverse tricortical screws and oblique quadricortical screws. Radiographs, before frame application and at frame removal, were reviewed. Tibial length, angular deformity, distal tibiofibular index (DTFI), proximal tibiofibular index (PTFI), and lateral distal tibial angle (LDTA) were measured. Malhotra grades and duration of external fixation were also recorded. Eighteen patients (21 limbs) were identified (transverse screws in 15 limbs and oblique screws in 6 limbs). Age and gender were similar for both groups. There was no significant difference in lengthening amount (transverse: 40 mm and oblique: 35 mm), angular correction, lateral malleolar and fibular head migration, LDTA change, and frame duration.
Results: After lengthening, and only in the transverse group, DTFI and PTFI changed significantly (DTFI pre: 12 mm, post: 8 mm, P = 0.01; PTFI pre: 17 mm, post: 22 mm, P = 0.02). Two ankles in the transverse group moved from Malhotra 0 to 1; however, no grade change was noted in the oblique group. No screw-related complications were encountered in either group.
Conclusion: Although migration of lateral malleolus was encountered in the transverse group, the amount of DTFI change was similar to the oblique group and no LDTA change was noted in either group. No advantage of one syndesmotic fixation method over the other was found in this study.

Context: The osseous and soft tissue anatomy of the knee in congenital longitudinal lower limb deficiencies is important to consider, both in limb lengthening procedures and in soft tissue reconstruction.
Aims: Our study aims to further define the patho-anatomy of the knee in this group of patients.
Methods and Material: 24 children were reviewed clinically and radiologically. Osseous and soft tissue anatomy is described including MR imaging of 27 affected knees.
Results: Our results echoed those of previous authors, with dysplasia of the menisci and cruciate ligaments a frequent finding. However, the study demonstrated that a clear correlation between the osseous anatomy and soft tissue findings was not always seen.
Conclusions: MRI allows assessment of the cartilaginous epiphysis in younger children with longitudinal dysplasia and we would recommend systematic assessment of the knee prior to any surgical intervention.

Background: Ollier's disease is a non-hereditary skeletal disorder. Orthopedic management of limb length discrepancy could be complex given the nature of bone pathology, the significant amount of length discrepancy and the difficulty to predict it. The goal of the study is to identify the outcomes and complications associated with surgical management of limb length discrepancy. Methods: This is an IRB approved, retrospective review of patients with Ollier's disease who had limb lengthening. The age at the time of surgery, amount of total length discrepancy and discrepancy for each individual bone, amount of lengthening and as a ratio to the length of the bone itself, type of fixator, duration of the fixator, complications are recorded. Unpaired T-tests evaluated the effect of simultaneous versus single-bone lengthening and tibia vs. femur being lengthened on the external fixator index. One-way ANOVA test was used to evaluate the effect of osteotomy location on mean External Fixator Index (EFI). Results: 14 patients with 40 segmental limb lengthening procedures are identified. The mean LLD was 7.1 cm and mean amount of length gained was 7.8 cm. Follow up was minimum 2 years and maximum 18 years 2 months. The average fixator duration was 178.6 days. The average percent of lengthening through each bone was 19.2. The average EFI was 36.5 days/cm. There was no difference between tibia vs. femur and between simultaneous vs. single bone on EFI. There was no difference among osteotomy type. There were 3 cases of nonunion, one delayed union, 5 cases of premature consolidation. One case had fixation failure. There were 7 cases of knee stiffness of which 3 cases required surgery. Conclusions: Our study shows that Enchondromal bone appears to respond to lengthening with a structurally proper regenerate. Premature consolidation needs to be always kept in mind and appropriate adjustment should be made in the rate of lengthening.

Quality of life of children with lower limb deformities: A systematic review of patient-reported outcomes and development of a preliminary conceptual frameworkHarpreet Chhina, Anne Klassen, Jacek Kopec, Sujin Park, Cadi Fortes, Anthony CooperJanuary-June 2017, 3(1):19-29DOI:10.4103/jllr.jllr_33_16

Background: Lower limb deformities have a substantial impact on the quality of life (QOL) of children. This systematic review was conducted to identify as follows: (a) QOL concepts in existing literature specific to pediatric patients with lower limb deformities; (b) parent-reported outcome and patient-reported outcome (PRO) instruments used to measure QOL in pediatric patients with lower limb deformities; and (c) determinants of QOL in pediatric patients with lower limb deformities. Methods: MEDLINE, EMBASE, CINAHL, and PsycINFO were searched from the inception to January 2016. Studies were included if they (1) had patients with lower limb deformities; (2) included children 18 years of age or under; and (3) measured QOL using a PRO or parent-reported outcome of instruments. Results: Of the 938 publications identified in the search, 10 studies used a total of 24 PRO or parent-reported outcome instruments to measure 1 or more aspects of QOL of pediatric patients with lower limb deformities. Three overarching health concepts (physical, psychological, and social health) and 15 subconcepts were identified. Five studies looked at determinants of QOL including type of deformity, severity of deformity, complications postsurgery, stage of treatment, and type of treatment. Psychological health was measured in 10 studies, social health in 7 studies, and physical health in 6 studies. The most frequently measured subconcepts were physical function, psychological distress, and social function. Conclusion: Existing parent-reported outcome and PRO instruments measure 3 QOL concepts in children with lower limb deformities. There were no validated PRO instruments specifically designed to measure QOL of children with lower limb deformities.
Level of Evidence: This was a systematic review of level III studies.